MailTester.ninja, Email Address Validator allows you to verify the existence of an email account without sending an email. Most email providers from any country, including gmail.com, hotmail.com, qq.com are supported.
A small number of email providers have disabled the ability to check for existence and provide the same response whether the email exists or not. Therefore, there are three email validation results: (1) email account exists, (2) email account does not exist, and (3) email account is unverifiable, its status is unknown.
The Mickey Mouse Paradox: Many other tools will estimate the validity of unverifiable emails based on email permutation statistics. In many cases they will very often consider emails starting whith mickey.mouse@ as valid: firstname.lastname@. Would Mickey Mouse work for many companies?